I have been running console2 for more than a month without any problems. However, after an anti-virus update, the application stopped working and clicking the Console.exe displays a dialog with error message, " Unable to start a is a test! "
Is there any change that needs to be done. (I have deleted its folder and used the latest stable release, but with same effects)
Console uses something called 'code injection' - a technique that's mostly used by malicious software. Just add Console to your AV's exclusion list.
It may have nothing to do with an antivirus. I managed to reproduce the exact error message when I put "is a test!" into Shell field of my tab. Maybe you experimented a bit too much?
If you run my unofficial build, you can start Console with -safe switch, so you can fix your settings. Otherwise, you can extract fresh console.xml next to console.exe. If it doesn't help, look into %appdata%\console and edit or delete console.xml from there.